SuperPro's SPF4396-27K is the replacement mount bushing for SuperPro's RC0050FZ-26 WRX front bar or RC0099FZ-26 WRX STI bar - the 26mm SuperPro bar requires a 1mm larger bushing to compensate for the thickness added from the epoxy coating and two-stage powder coat. This bushing kit will also work with other 27mm bars. Sway bar mount bushings are one of the most underappreciated components in your suspension system. Responsible for anchoring the sway bars and facilitating proper function and body control of your vehicle the OEM rubber bushings are tasked with quite a job and in-turn wear quickly compromising the effectiveness of your sway bar and contributing to a loose, sloppy feeling on the road over time. SuperPro's sway bar mount bushings are designed to fit the OEM designed hardware and mountings - no generic one-size-fits all bushings and cheap universal hardware here - each bushing is designed to integrate into the factory suspension design and function. Additionally grease retention technology is used in each bushing we make for a lifetime of smooth and silent operation turning a frequent maintenance item into a one-time repair upgrade to keep your vehicle driving like new; for life.